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Williamsport, Pa.

ph-6.4..lime added
acididy-2.8
k-1.4
mg-3.6
ca-18.8
om-13.2
%saturationof thr cec
k6.1
mg-15.8
ca-65.8
cec-22.8
any help on what to add would bw appreciated, thanks scott

11/7/2007 3:38:06 PM

Windsor, Ontario, Canada

What are the units for your soil test? For example, Ca 18.8 what?

11/16/2007 7:25:46 PM

Williamsport, Pa.

hello jorden, i know crap about this, im trying to learn.. exchangeable citations(meq/100g} thats the 18.8 cal..what ever that means..the top k-mg-ca-are exchangeable the bottom are % saturations.. thanks, scottie

11/16/2007 7:44:39 PM

Windsor, Ontario, Canada

First, we know these without any coNfusion:

Organic Matter (OM) 13.2%
This is great where it is. We know that when OM breaks down, it releases nutrients. The higher the OM, the less need we have for additional fertilizers. 13.2% is perfect. I have seen 20-25%, but I think that is too much.

pH. 6.4
The magic range is 6.5-7.0 so you are pretty good. You said you added lime, how much? I would just leave this now and see what happens on your next test in the spring.

Some brief points regarding CEC from the following site (http://hubcap.clemson.edu/~blpprt/bobweb/BOBWEB23.HTM):

- The CEC is the abbreviation for the cation exchange capacity.
- It refers to the the basic cations, calcium (Ca+2), magnesium (Mg+2), potassium (K+1) and s odium (Na+1) and the acidic cations, hydrogen (H+1) and aluminum (Al+3)
- CEC is expressed in milliequivalents per 100 grams (meq/100g), and it represents the amount of these positively charged cations a soil can hold (the larger this number, the more cations the soil can hold).
- A clay soil will have a larger CEC than a sandy soil
- CEC gives an indication of the soils potential to hold plant nutrients.
- Increasing the organic matter content of any soil will help to increase the CEC since it also holds cations like the clays.

The best values for the base saturations ratios depend on your CEC. Albrecht ratios have been mentioned by Tom Bohica on this site before:

Light or sandy soils (CEC <5) - % Ca 60, % Mg 18-20, % K6-8, % Na<3, % H 10-15
Medium or loamy soils (CEC 5-10)-% Ca 65-70, % Mg 10-15, % K 3-6, % Na<3, %H 10-15
Heavy or clay soils (CEC >10)- % Ca 68-75, % Mg 10-12, % K 2-5, % Na<3, % H 10-15

Your CEC is even higher, as is mine. I think a good set of percentages for you would be roughly (dont mind the math)

Ca 75-85, % Mg 8-10, % K 2-3, % Na<3

11/16/2007 9:06:42 PM

Windsor, Ontario, Canada

Now, as for the macro nutrients, I don't have much experience with the units being used. I did some reading though, so here is my best guess. Check out this site: http://www.soils.umn.edu/academics/classes/soil3416/discussion8A.htm


Atomic weights for these elements are: Ca=40, Mg=24, Na=23, K=39, and H=1. Use the conversion factor 2,000,000 lbs of soil/acre 6-inches

First step is to convert meq values to weight values, so that you can express amounts of the exchangeable elements on a weight (lb/acre) basis

meq * mg/meq = mg


Ca (example conversion)

meq weight of Ca = 40 mg/millimole * 1 millimole/2 meq = 20 mg/meq (Ca is divalent, so there are 2 eq/mole or 2 meq/mmol)

18.8 meq Ca/100 g soil * 20 mg Ca/meq = 376 mg Ca/100 g soil

mg/kg = ppm

376 mg Ca/100 g soil * 1000 g/kg = 3760 mg Ca/kg soil = 3760 ppm Ca in soil

2 million lb soil/acre, so ppm * 2 = lb/acre

3760 ppm Ca * 2 = 7520 lb Ca/acre



The ppm conversions should be:

Ca - 3120 - The Ca is fine, but could go up to as much as 4000ppm (best range 3000-4000)
Mg - 432 - Mg should not go much higher, it is fine where it is. (best range 250-400)
K - 273 - K could go up a bit (manue would take care of this for you (best range is 300-500)
P I didnt see any P in the test results. (best range 100-150)


Before I mentioned Ca 75-85, % Mg 8-10, % K 2-3, % Na<3. These are not the only important ratios. There are two other ratios which are important. Those are Ca/Mg and Ca/K. Being too far off these ranges will affect nutrient uptake.

Ca/Mg should be roughly 10-12, you are at 7.2. You need more Ca.
Ca/K should be 8-10, you are at 11.4. More Ca will take care of this too.

MY RECOMMENDATIONS ARE AS FOLLOWS, FOR WHAT THEY ARE WORTH. MORE CALCIUM WILL BRING YOU INTO A GOOD BALANCE. A LITTLE MORE K WOULDN'T HURT EITHER. PERHAPS SOME POTASH. PRETTY GOOD IN GENERAL THOUGH. I WOULD WAIT TO SEE IF ANYONE ELSE COMMENTS ON WHAT TO ADD TO BRING YOU K UP. NOT SURE IF POTASH IS THE

11/16/2007 9:06:54 PM

Williamsport, Pa.

thankyou jorden, now after i read and re read this a few times ill get a better look at whats going on in the dirt.. more gypsum will be going in, this week. as for the potash i through on some 0-0-60 last week to get rid of it out of my shed, as to not give me any temptations next summer, thanks again, scott

11/17/2007 6:37:02 AM